Astronomer Reynolds's two far-future space exploration novellas, set in his Revelation Space universe (Chasm City , etc.), confirm his mastery of noir SF. Antihero Richard Swift of "Diamond Dogs" joins Mephistophelian Roland Childe's expedition to scale the Blood Spire on the planet Golgotha. As they climb, they must solve increasingly intricate mathematical puzzles, replacing limbs and mental processes with cybernetic constructs as the Spire changes the rules of its lethal game. Naqi Okpik of "Turquoise Days" loses her sister Mina to the sentient ocean of the planet Turquoise. Naqi abandons her humanity, uniting with the ocean to find Mina and save their world from destruction. Spire and ocean are both artifacts of Revelation Space's alien Pattern Jugglers, who form a living gestalt interstellar entity that in these brilliantly executed parables represents the vehicle for humanity's choice between self-immolation and evolution and the author's postulated solution to the riddle of Faustian man. Reynolds's allegory: if humans embrace science and technology so fervently that body and soul sacrifice themselves to overweening greed, humans will eventually perish in bitter suicide; instead, abandon selfish individuality, immerse the soul in the warm sea of homecoming where minds meet and meld into oneness, and survive, changed forever. Agent, Robert Kirby of Peters, Fraser and Dunlop (U.K.). (Jan. 4)